Virachai Kerekhanjanarong

Genomic alterations in nasopharyngeal carcinoma: loss of heterozygosity and Epstein-Barr virus infection

Nasopharyngeal carcinoma is a subset of head and neck squamous cell cancers with unique endemic distribution and aetiological co-factors. Epstein-Barr virus has been revealed to be an important aetiological factor for most nasopharyngeal carcinomas. Nevertheless, additional genetic alterations may be involved in their development and progression. The aim of this study was to determine the likely chromosomal locations of tumour-suppressor genes related to Epstein-Barr virus-associated nasopharyngeal carcinoma. Fifty-six microsatellite polymorphic markers located on every autosomal arm were used to estimate the incidence of loss of heterozygosity in 27 Epstein-Barr virus-associated nasopharyngeal carcinomas. High frequencies of allelic loss were observed on chromosome 3p (75.0%) and 9p (87.0%). Chromosome 9q, 11q, 13q and 14q displayed loss in over 50%, while chromosome 3q, 6p, 16q, 19q and 22q exhibited loss in 35-50%. Furthermore, several other chromosomal arms demonstrated allelic loss in 20-35%. Additionally, 1 of the 27 cases showed microsatellite instability at multiple loci. These findings provide evidence of multiple genetic alterations during cancer development and clues for further studies of tumour-suppressor genes in Epstein-Barr virus-associated nasopharyngeal carcinoma.

KTP laser inferior turbinoplasty: an alternative procedure to treat the nasal obstruction

OBJECTIVE Nasal obstruction resulting from inferior turbinate hypertrophy (ITH) was treated with KTP laser inferior turbinoplasty (KIT). The effectiveness of the procedure was assessed. METHODS A prospective clinical trial was carried out in King Chulalongkorn Memorial Hospital from October 1, 1998 to September 30, 2000. Forty-eight patients with chronic nasal obstruction underwent KIT. Nasal obstruction was pre- and postoperatively assessed, based on 4-point scale, by the patient and investigator. The scores were compared by paired t-test. The correlation of assessment by the patient and investigator was also demonstrated by weighted kappa test. Pre- and postoperative rhinomanometric evaluations were performed in 29 patients and were compared with paired t-test. RESULTS Significant reduction of nasal obstruction was obtained from assessment by the patient (P<0.000) and by the investigator (P<0.000). The symptoms of sneezing, itching and rhinorrhea were significantly reduced postoperatively (P<0.000). The cure and improvement rate of nasal obstruction were at 70.8 and 100% (assessed by the patient) and at 77.1 and 100% (assessed by the investigator) respectively, and they showed a moderate correlation (Kw=0.65). Rhinomanometrically, the total airway resistance decreased but of not statistic significance (P=0.219), however, the inspired nasal airflow at 150 Pa and the volume of nasal cavities were significantly increased (P<0.00 and P<0.001, respectively). CONCLUSION KIP was shown to effectively reduce the symptom and sign of nasal obstruction as well as other nasal symptoms without any significant complications. It should be an alternative method in treating the patients with nasal obstruction resulting from hyperplastic inferior turbinate.

Auricular pseudocysts: A treatment with the Chulalongkorn University vacuum device

Auricular pseudocysts are rare lesions that present as an asymptomatic cystic swelling of the anterior surface of the auricle, particularly the antihelix. Typically, the pseudocysts contain viscous straw-yellow fluid similar in appearance to olive oil; however, a clear pale yellow serous transudate may also be encountered. Various therapeutic approaches have been used with variable success. We describe a simple small vacuum device called the Chulalongkorn University vacuum device, which was developed in our center. The device can be easily made anywhere by any surgeon. We report the outcome in 17 patients treated by means of needle aspiration plus application of the Chulalongkorn University vacuum device for 5 days. A complete resolution of the lesion was obtained in 15 (88.2%) patients. Because the procedure is safe and effective and does not require an operating room setting, it may be accepted as an option in the treatment of auricular pseudocysts.

Telomerase assay and nested polymerase chain reaction from nasopharyngeal swabs for early noninvasive detection of nasopharyngeal carcinoma

The main purpose of this study was to analyze sensitivity and specificity of combining nested polymerase chain reaction for detection of Epstein-Barr virus (EBV) genome and telomerase assay for identifying nasopharyngeal carcinoma (NPC). Eighty patients with NPC and 27 healthy control subjects were included in this study; 97.5% and 94.9% of NPC patients were positive for EBV genome and telomerase activity, respectively. When nasopharyngeal swabs were tested, 95.7% presented the EBV genome and 85.5% were positive for telomerase expression. The sensitivity for counting either positive result of these two techniques was 100%. Among the 27 control subjects, only 6 and 5 cases were positive for EBV DNA and telomerase activity, respectively. This indicated a specificity of 92.6% when both positive results were included. At present, early diagnosis of NPC requires multiple biopsy specimens, especially to identify subclinical cases. Because this study showed a very high sensitivity for detecting NPC from swabs when combining the telomerase assay and nested polymerase chain reaction technique, this noninvasive technique may be a good candidate for screening of subclinical NPC, especially before multiple biopsy specimens are obtained.

Auricular pseudocysts: A treatment with CU-VAC

of therapy/no intervention, and again after another 6 to 8 weeks. Analysis was conducted using SPSS(X). Results: Voice therapy improved self-rated (F = 12.2, P = 0.001), and expert-rated voice quality (F = 17.5, P < 0.001). Therapy also improved one acoustic analysis parameter-shimmer (amplitude perturbation: F = 5.9, P < 0.01); however, this effect was not sustained at follow-up. There were no differences between the groups in psychological distress or quality of life over time. Conclusion: (1) Voice therapy for dysphonia is an effective treatment in terms of subjective reports. (2) Most objective acoustic parameters showed poor correlation with global reports of voice quality. (3) Voice therapy had surprisingly little impact on psychological distress or general health status.